Agitator



June 4, 1929. J. E. BOND 1,716,299

AG I TAT OR Filed March 5, 1928 Patented June 4, 1929..

STATES nf' ntio relates to the art of paper f'ie. e f r a inent' preceding deliveryate" the Fourdriniers.

hile. n h e r c 21/2%-*P111P'W1-S coirsideiai.-1.preper;isand of the maximum density possible, it isnow common to deal with 6% solutions, with eorrespondlngly increased production capacity.

However, many diflicult problems are encountered in handling pulp of this density due to its lack of fluidity and its tendency to mass or cake in the storage or treatment tanks and containers. This tendency is 1nherent in the nature of the material under treatment due to its fibrous character and to the physical law of attraction of solids. The liquid within which the solids are carried serves merely as a supporting medium therefor and facilitates rather than hinders the massing and intertwining of the fibers.

To avoid massing and stratifying of the pulp in the liquid and to maintain a uniform density throughout the entlre body of material it must be kept in motion and the motion producing means should have a tend- I ency to break up and tear apart any large or small masses of pulp. In the old practice the mixture was kept in motion by means of paddles or impellers in the tank,

but this apparatus had very little tendency to break up masses of pulp, and was wholly inefi'ective with stock of increased density. Furthermore, such apparatus required an outlay of power not commensurate with the results secured.

The tanks, chests or containers which are in place and must be utilized for the new plan of operation are of many and varied forms, all of great size, some narrow and of great length, some deep and some round. The problem has been therefore, to provide means applicable to t ese various'forms of tanks that would insure efi'ective circulation, the breaking up of pulp masses and the maintenance at all times of a proper consistency throughout the whole volume of material, with a minimum of power expenditure.,

I p en ofthe art'itj has been 5 f und possibleto gfeatly increase the cap'a'cityg 'of af given-fequi ment by increasing PATENT OFFICE.

' Josnrnn norm, or nrrrnromwrsconsmnerm'ron.

[Application area mm; 5, 1928. Serial No. 259,091.

My invention will be more readily understood by reference to the accompanying drawings, of which F'g. 1 is a plan view of a tank with my improved agitating means therein, and

Fig. 2 is a transverse vertical sectional view therethrough.

In the drawings I have illustrated a tank of relatively great size having a floor 10 and a circular side wall 11. Arranged within the tank and extending vertically upward from the floor are walls 12, 13 bent or formed to a generally volute outline, one end of each wall being directly connected to or abutting the side wall of the tank at dia metrically opposite sides thereof. The walls 12, 13 are so arranged as to form two passages, A, B, that gradually converge toward the center and unite in a chamber 0 at the center of the tank. While the passages conform the arc of a true circle for a portion of their length, the general efiect is that of a volute curve.

In order to secure eflieient circulation of the large body of liquid, I provide two pumps 12, 13 at diametrically opposite sides of the tank and exteriorly beneath the same. To the inlets of these pumps is connected a large pipe 14 extending beneath the tank and having a vertically extending branch 15 that opens through the floor of the tank at the center thereof. Discharge-pipes 16, 17 are connected to the outlets from the pumps and extend vertically near the outer wall of the tank to a point near the top thereof and at the beginning of the passages A, B.

A quantity ot pulp being contained within the tank and the pumps being in operation, the material is drawn into the pumps through the opening 15 and the pipe 14 and is thence discharged upwardly through the pipes 16, 17; thereafter it flows alongv the passages A, B toward the center of the tank and finally reaches the middle chamber. C from which it is again drawn into the outlet pipe. This provides an eificient means of circulation and assures proper consistency let discharging into a passage near the exterior wall of the tank at a higher level than thatof the inlet.

. 2. In combination, a circular tank, wallsv therein shaped to provide a plurality of passages that converge toward the center of the tank and that are of substantially the depth of the tank walls, a pump, a pump inlet 'pipe communicating with the center of the tank through the floor, and a. pump outlet-pipe extending upwardly and discharging into a passage at a point remote from the inlet to the pump.

' 3. In combination, a circular tank, means therein providing a plurality of generally volute assages that unite at the center of the t'a a pump connected to draw material from the tank at the confluence .of said passages and to discharge materials into a passage at a different elevation and at a point remote from the inlet.

4. In combination, a tank, means therein providing a plurality of passages that gradually converge from the exterior to the center of the tank, a-plurality ofpumps each having an inlet at the point of confluence of said passages, and each having a discharge outlet into a difierent passage at a point near the beginning of the passage.

.5. In combination, a circular tank, walls therein arranged to provide a plurality of spiral or volute passages, said passages terminating in a chamber at the center of the tank, pumps arranged on opposite sides of the. tank, each pump having an inlet pipe communicating with the bottom of said central chamber and each pump having a discharge pipecommunicating with an elevated point at the start of a'passage. In testimony whereof I have aflixed my signature.

JOSEPH E. BOND. 

